Iris defects occur in pseudophakic patients with posterior chamber intraocular lens in sulcus. Prevalence of pigmentary dispersion syndrome and pigmentary glaucoma has been evaluated in 920 pseudophakic patients (920 eyes). 16.08% of patients showed pigment dispersion syndrome, while 1.96% developed pigmentary glaucoma. Diabetic patients had a statistically significant greater prevalence of these complications than non-diabetic ones (p < 0.05). The authors suggest the preventive use of alpha-blockers in presence of pigment dispersion syndrome or diabetes mellitus, even in absence of ocular hypertension.